I've had a vegetable garden the past 4 summers, but this is my first crack at growing flowers (other than marigolds)

I ordered some tubers from Holland bulb farm and I'm set on how to deal with those, but I ordered some seeds from Hazzard's Greenhouse and those have me a little bit more stumped

It says on Hazzard's website they will only sprout at 60-67 degrees F. If I start them inside (we are no where near the 60s today in Chicago) will that be ok? Do they transplant well? As soon as they sprout I plan on getting them outside (weather should be more stable in a week or two) so I don't anticipate hardening off to be an issue

The other issue is I don't want a lot of the darker colored flowers, but since it was a mixed packet of seed (I ordered the pompon variety and showpiece) is there anyway to tell? A post below shows red growth, but the variety is white? Will the seeds all look exactly the same (it's set to be delivered today)

http://www.hazzardsgreenhouse.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=Hazwho&Product_Code=D6450&Category_Code=DahliaA#.U3T1DN606Uk